This thing is ridiculous. Anyone that knows anythign about engineering and physics can easily calculate that their performance claims are false, and, at the speeds they propose, wings are far more efficient. In short, this proposal is hardly eco-friendly, and they can’t possibly know what they’re doing if they, and I quote, “…don’t want to be carrying around gallons and gallons of heavy petrol or diesel and we are looking into fuelling it with some form of helium gas.” Morons! Helium isn’t combustable.